it’s a big internal contradiction within china. your hukou(where you’re registered) determines what benefits you have and so its a lot harder for rural residents to work/get benefits/get schooling for their kids. I’ve also heard my mom mention there’s some discrimination/you’d get looked down on from being on the countryside. However, it was necessary to prevent slums from existing and now the restrictions are being relaxed, primarily starting in like 2nd/3rd tier cities i believe.

Edit: Here's an article about the progress and rationale behind the hukou system(in english). The rural-urban divide is very clearly noted to be a primary contradiction

“What we now face is the contradiction between unbalanced and inadequate development and the people’s ever-growing needs for a better life,” he said. The evolution of the principal contradiction represents a “historic shift that affects the whole landscape and that creates many new demands for the work of the Party and the country,” Xi said. Previously the principal contradiction was described as one between “the ever-growing material and cultural needs of the people and backward social production.” (quote not from article, from here)